Cathode-ray translating system for permutation codes



w. T. RE A ,6 78

CATHODE-RAY TRANSLATING SYSTEM FOR PERMUTATION CODES Oct. 6, 1953 3 Sheets-Sheet 1 Original Filed Aug. 29, 1944 INVENTOR w. TIRE/4 ATTORNEY Oct. 6, 1953 I w. T. REA 2,554,378

CATHODE-RAY TRANSLATING SYSTEM FOR PERMUTATION CODES Original Filed Aug. 29, 1944 3 sheets-shed 2 Flaz Pi -P100097 mam Lerraks 1234s A; TORNEV W. T. REA

Oct. 6, 1953 CATHODE-RAY TRANSLATING SYSTEM FOR PERMUTATION CODES -3 Sheets-Sheet 3 Original Filed Aug. 29, 1944 kzuESu 32.56 o2 u Evin oQ u 3.59. @8333 .En Q

Patented Oct. 6, 1953 GATHODE-BAY TRANSIATINGL SYSTEMFOR. PERMUTATION CODES Wilton T. Rea, Manhasset, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New

York, N. Y., a. corporation of New York Original application August 29, 194:4, Serial No.

551,674, new Patent No. 2,458,030, dated Jane nary 4', 1949..

Divided and. this application December 4, 1948, Serial No. 63,597

16 Claims- This invention relates to signaling apparatus and systems and more particularly to circuit selecting or decoding arrangements used in such systems.

granted January 4, I949.

the. system.

coded message is to. be interpreted.

the. circuit by the code unit circuits.

2 potential established at the output terminal by a code combination may be used.

Further objects and features of the invention will appear from the following detailed descrip- This application is a division of copending aption of specific embodiments of the invention. piication Serial No. 551,674, filed August 29, 1944, In the following description reference will be by W. T. Rea, which has issued as Patent 2,458,030 made to the drawings in which:

Fig. I shows a telegraph signal receiving system It is an object. of the invention to provide a adapted for operation on a. seven unit Start-Stop circuit selecting or decoding arrangement in telegraph code for setting up the five selecting which the various code permutations are reprecode units on live output conductors respectively; sented by distinct potential difierences of sufil- Fig. 2 shows a decoding circuit having five incient magnitude to insure accurate discriminaput conductors adapted for connection to the tion inany one of the discriminating circuits in output conductors of Fig. 1 and arranged for 115 translation of a telegraph message into symbols It is a. more specific objectto provide a type 01. made visible by means of a cathode ray tube; circuit selecting system which may be effectively Fig. 3 shows 'diagranmmatically a field of letters, used in code signaling systems such as the mesnumerals and signs which may be arranged on sage circuits in telegraph systems in which the the reading surface of the cathode ray tube in 29 Fig. 2 for visible display of the symbols of a In accordance with the invention the system message; includes a circuit selecting arrangement the main Fig. 4 is a diagram of operations for the system features of which are a code'unit circuit for each shown in Fig. 1; unit of the code adapted to respond to the alter- Fig. 5 is a fragmentary perspective view of the note characteristics of its assigned code unit, cathode ray tube showing an alternative arrangeand code discriminating circuits for the comment of the reading surface with electrodes inbinations of the code or for the circuits to be stead of symbols. selected or for the symbols which it is desired The receiving circuit shown in Fig. 1 includes to translate from the code. Each code unit cira. receiving relay till having an upper winding cult has. two output conductors one of which has connected to an incoming circuit- L for receiving a. high potential and the other a comparatively marking and spacing pulses. It will be assumed low potential, under marking condition, these that the marking condition is established by ourpctentials being interchanged between the two rent in the circuit L and the spacing condition conductors under spacing condition. Each code by no current therein. The relay has a. lower discriminating circuit. includes a potential gradbiasing winding continuously energized to. hold ient network with a plurality of branches con the relay armature against the spacing contact nectedto the output conductors from the code when the upper winding is currentless. A markunit circuits in accordance with the code requireing current in the upper winding will be strong ments for the particular symbol represented by enough to overcome the biasing winding and the code discriminating circuit. The arrange 40 operate the relay to marking. The relay I20 has ment or the potential gradient circuit is such a marking and a spacing contact connected to that an intermediate control potential is estabplus and minus potentials, respectively, for aplished' at an output terminal thereof which will plication to the circuit. have difie'rent distinct values in accordance with The system includesa grounded source of direct the different code combinations impressed: upon &5 current H0 which applied volts to parts By this of the system, and another grounded source of arrangement it. ispossible to select a particular potential H l applying a potential of -48 volts potential for any code combination to which the to other parts oi'the system. For the sake of simcode discriminating circuitshould respond ior plicity, all conductors shown in Figs. 1 and 2 selection or translation by impressing the poten- 56 which are directly connected to the source ll 0 are tials at the output. terminal upon a sensitive disterminated in a 6+) symbol indicating that they criminating device which is made selectively reare to be interconnected directly and all consponsive thereto. For individual selection, as for ductors connected directly to the source III are the selection 01' a single symbol out of a plurality 5 terminated in; 2.- symbol indicatingthat theyof sym ol e t er the maximum or the minimum are to be directly interconnected.

The circuit in Fig. 1 includes an oscillatory circuit I30 and a vacuum tube I40 associated therewith for feedback to produce sustained oscillations. Other vacuum tubes I50, I60 and I are provided to apply impulses to other parts of the circuit in synchronism with the oscillations. These vacuum tubes, and other vacuum tubes used in the system and referred to hereinafter, may be of conventional type, each including the heated cathode or filament, the control element or grid and the anode or plate, mounted in a highly evacuated container or tube. With a substantially constant potential applied between the plate and the cathode, the current in the cathode-anode circuit is controlled by the potential difference between cathode and grid, becoming less as the grid becomes less positive or more negative with respect to the cathode. Thus for any particular tube there will be a certain critical grid potential at which the plate current is so small that for the purposes of the system the tube may be considered extinguished or non-conducting; at grid potentials above the critical value the tube may be considered fired or conducting.

The circuit further comprises an electronic distributor including a series of distributor gasfilled tubes DG, one of these tubes being assooiated with the Start pulse and another with the Stop pulse and the five intervening tubes DG being associated with the five significant or selecting pulses I, II, III, IV and V, respectively. The latter five tubes DG are each associated with a storing gas tube SG and a transfer gas tube TG. The gas-filled tubes DG, SG and TG, and other gas-filled tubes used in the system and referred to hereinaften'may be of conventional type, each including a narrow control gap between the cathode and the control anode and also includin a main gap between the cathode and the main anode or plate. These elements are included in a sealed vessel or tube containing a suitable inert gas at low pressure. A comparatively high firing potential is required to break down the control gap for firing of the tube, and with a comparatively low sustaining potential applied to the main gap the discharge will automatically switch to the main gap. In order to extinguish the tube the firing potential and the potential across the main gap must be reduced below their sustaining values. From each of the transfer tubes TG an output conductor I00 is provided for impressing the stored combination upon other circuits. A relay I90 is arranged for operation during the Stop pulse and serves to control the transfer of the stored combinations into the circuit in Fig. 2 during the Stop pulse.

The circuit in Fig. 1 is shown in normal stop condition with relay I in marking position and relay I80 in spacing position.

The oscillatory circuit I30 and its associated feedback tube I40 and output tube I50 are particularly arranged for operation on a start-stop basis and for the production of short impulses evenly and accurately spaced apart in synchronism with the standard frequency of the telegraph signals received over the circuit L. Such a Start-Stop pulse producing circuit, substantially identical with that shown in Fig. l is disclosed in Patent 2,370,685 granted March 6, 1945, to W. T. Rea and J. R. Wilkerson.

The circuit I30 includes an inductanc I3I divided into two closely coupled halves and a condenser I32. A potentiometer I33 is bridged across the left half of the inductance to apply oscillatory potential to the control grid of the vacuum tube I40; the cathode-anode circuit of tube I40 is connected across the right-hand of inductance I3I through plus battery and ground for energy feedback during each oscillation. The oscillatory circuit I30 is normally held cocked against oscillation by the application of plus potential over marking contact of relay I20, conductors I2I and I24, gas tube I and conductor I35 connected to the output terminal T of the oscillatory circuit; the gas tube I80 is normally in conducting condition. The circuit is so adjusted that under this condition a current flows through inductance I3I of the same magnitude as the maximum current flowing during oscillations.

Upon receipt of a Start pulse, which is a spacing pulse, relay I20 operates to spacing and opens the cooking circuit, just traced, thereby removing the pulse potential from the terminal T. The stored energy in inductance I3I now transfersto condenser I32 and a first cycle will be produced without any superimposed transients and the system continues to produce identical cycles until the'arrival of the next Stop pulse when it will again be cocked over the marking contact of relay I 20, the cocking circuit in the meantime having been kept open by the tube I80, as will be described hereinafter.

The oscillations are impressed upon the control grid of the output tube I50 which for certain values of the varying voltage applied to the grid becomes conducting and non-conducting, at each change producing a short impulse in the secondary winding of the transformer I52, which impulses are impressed upon the dis tributor circuit over conductor I53.

The oscillations are also impressed upon the grid of tube I60 which similarly becomes conducting and non-conducting at predetermined values of the oscillating potential. When the tube N50 is non-conducting the'condenser IE4 is charged from minus over resistances I65, I03 and to plus potential on the potentiometer I62. The moment the tube I60 becomes conducting the condenser I64 temporarily impresses a negative potential on the grid of the normally conducting tube I10 which thereby is temporarily extinguished. This shift of the condenser voltage is caused by the drop in potential over resistance I63 due to the rising plate current in tube I60; as condenser I64 discharges to the reduced potential the grid potential in tube I10 is restored to its former value and the tube again becomes conducting. When tube I60 is extinguished at a later instant of the cycle of oscillations, the drop over resistance I63 disappears and the condenser voltage is shifted toward plus, thereby making the grid of tube I10 more positive and temporarily increasing the plate current, without significant efiect until the condenser resumes its new charge. Each time the tube I10 is rendered conducting or nonconducting an impulse is produced in the secondary of transformer I12 which is applied to the control anodes of storing gas tubes SG over a circuit from marking or spacing contact of relay I20, conductors I2I and I22, secondary winding of transformer I12 and conductor I23; the impulses from transformer I12 thus are superimposed upon the plus or minus potentials applied by relay I20 to the storing tubes.

In the following description of the operation 0. the different parts of the system shown in Fig.

amaze 1, reference willalso be made to the diagram of operations shown in Fig. 4..

This diagram includes a set 01' horizontally disposed curves A to M representing corresponding functions occurring at different points or the system during the reception of a series of pulses of an incoming code signal. The code signal. comprises the Start transition, the selecting or character transitions 1,. II, III, IV, V and the Stop transition and. the arrival times of these transitions are indicated by correspondingly identified vertical lines extending across all of the curves, transitions III and IV having been omitted for simplification. The transition lines indicate the standard arrival times for the system in accurate relation to the arrival time of the Start impulse of the received signal and thus do not indicate bias or other distortion.

The curves C to M are not intended to show accurately the details of variations in currents or voltages, but merely serve to indicate the instants at which changes take place and the general nature of the changes.

Curve A shows the pulses of the signal incoming to relay I20". normally a marking condition is received until the Start pulse operates the relay to spacing and thereby establishes the reference instant for the succeeding operations. The code will, for the sake of example, be assumed to be as follows: the Start pulse; selecting pulse I, which is marking and is delayed; pulses II and III, which are marking; pulses IV and V, which are spacing; and the Stop pulse which is assumed to arrive early. The relay I20 thus will operate from spacing to marking at the times 401 and 403 marked on the curve A.

Curve B shows the oscillating voltage at the terminal T of oscillator I30. During rest condition the potential at T will be slightly positive due to the resistance drop in inductance I3 I. Upon arrival of the Start transition the oscillator produces a series of seven substantially pure harmonic voltage oscillations, each odd half cycle being negative and each even half cycle being. positive. The duration of each cycle equals the standard pulse period.

Curves C, H and J show the variation in plate current in tubes I50, I60 and I10, respectively, as controlled by the oscillations, and curves D and K show the corresponding voltage impulses produced in the secondary windings of transformers I52 and I12, respectively. The critical grid potential for tube I50 is shown in connection with curve B by the dot-dash line ISO-critical, being more positive than the normal pulse potential at point T before the Start, so that the tube is normally nonconducting. At the time IIl during the positive half cycle and near the center oi the Start pulse tube I50 becomes conducting, and at the time 4I2 near the end of the cycle the tube again becomes currentless. The critical potential may be changed by adjusting potentiometer I5I. The critical grid potential of tube IE0 is similarly shown with. curve B by dot-dash line IGII-critical and thus the tube, being normally currentless, becomes conducting at the time H3 and. currentless at time M4 during the positive half cycle. The variations in grid potential for tube I relative to the critical potential are shown in curve I.

For the purpose of orientation during opera.- tion the instants at which the tube I60 becomes non-conducting may be phased relative to the standard transition instants established by the oscillators circuit I30 by means oi the potentiwinding.

ometersi MI and I02, the adjustable contacts of which may be ganged together ilor simultaneous adjustment, so that the cathode-anode potential may be: kept constant, once adjusted, while it is shifted relative to the grid potential. Accordingly. the potential line "IGIl-critical may be shifted: above or below the zero line for curve B, with the object of securing the: best operation for any general bias or other distortion. of the sigmale;

The operations referred to above as taking place at the: instants. I, 41.2,. 3 and 4 during the first cycle of oscillations will, of course, be repeated at corresponding instants during each succeeding cycle;

Curve E shows the times of current flow in or firing of each of the distributor gas tubes DG. The: tube DG-Start is normally fired.

Curve F shows the operation of transfer relay I00 to marking during the Stop pulse.

Curve G shows the firing of the Stop gas tube I80 at the end of the signal.

Curves L and M. relate to the functions of the storing gas tubes SG and, for the sake of clear- .ness, these curves show the variations in control potential and the firing times, respectively, for only the tube SG-I, which stores: the selecting pulse 1..

The operations of the impulse producing circuit will now be briefly traced.

Upon operation of the receiving relay I20 to spacing at the Start transition the Stop tube I80 is extinguished and the oscillator I30 enters its first negative half cycle. No change takes place in the impulse producing circuit until the time 4H during the positive half cycle when tube I50 becomes conducting. The rise in plate current produces a short negative pulse in the secondary winding of transformer I52 which has no efiect.

At instant 3- tube I becomes conducting,

thereby temporarily shifting the grid potential for amplifying tube "0 through condenser I64 and momentarily rendering tube I10 nonconducting. This causes the transformer I12 to produce a short strong positive impulse, followed by a short weak negative impulse in its secondary The positive impulses produced by transformer I12 in this manner are used for the selective control of the storing gas tubes SG, as

an increase in grid potential will result in a comparatively small increase in plate current.

The resultant negative and positive impulses produced .at this time in the secondary winding of transformer II2 therefore will have no effect.

At the time M2 the tube I50 is rendered nonconducting thereby producing a positive impulse in the secondary winding of transformer I52 which is utilized for control of the gas tube distributor, as will be described hereinafter.

The operations just described will be repeated during subsequent cycles and under the control of the oscillator, these operations being independent of the incoming pulses and the operations of relay I20. Seven complete similar cycles will be produced in this manner, and exactly at the end of the seventh cycle, which occurs during the Stop pulse, the oscillator is cocked by the refiring of Stop tube I 80, as will be described later, and the impulse producing circuit is restored to its normal or waiting condition.

It will thus be seen that an effective impulse is produced by transformer I52 at each standard transition instant for advancement of the distributor circuit, and that other effective impulses are produced by transformer I12 at orientable instants near the middle of the standard selecting pulse periods for control of the storing circuit.

The electronic distributor circuit, as already stated and as shown in Fig. 1, includes seven gas tubes DG. Each tube has associated therewith a resistance R! and condenser CI connected to the control anode and a resistance R2 and condenser C2 connected from minus to the cathode; the main electrode is connected over the common resistance I 85 to plus. The resistance Ri connects the control anode with the cathode of the preceding tube and the condenser CI connects the control anode to the impulse conductor I53 from transformer I52.

Still assuming that the system is in stop condition, all the distributor gas tubes D6- are nonconducting except the tube DG-Start.

Considering any one of the currentless tubes, such as DG-I full minus potential is applied over resistance R2 to the cathode and plus potential is applied over common resistance I85 to the main anode; condenser C2 is discharged over resistance R2. Full minus potential is applied over resistances R2 and R! in series to the control anode; condenser CI is charged from minus over resistances R2 and RI and the secondary of transformer 52 to ground. Thus the main gap has ample sustaining potential, whereas the control gap has direct minus potential on both sides.

Considering now the current condition in the tube DG-Start, electron current flows from minus over resistance R2. The cathode and main anode, primary winding of transformer I82, common resistance 185 to plus; the potential drops in resistances R2 and IE reduce the voltage across the main gap to near the sustaining value. Condenser 02 is charged across resistance R2. A biasing plus potential is thus applied to the control anode of tube DG-I through resistance RI-I. The condenser CI-I was previously discharged from its minus potential and has been subsequently recharged from the biasing plus potential and through the secondary of transformer 52 to ground. The circuit remains in this condition until the arrival of the Start pulse.

Upon the arrival of a Start pulse relay I20 operates to its spacing contact, thereby applying negative potential to' the conductors I22 and I24. The tube I89 is extinguished and the oscillator circuit 130 is uncooked so that the first cycle of oscillations will operate the tubes I50, I66 and 1H? as described above.

The first short plus impulse from transformer 452 is applied to all the condensers CI. This plus potential thus is momentarily added to the biasing plus potential already present on the control anode of the tube DG-I, the total potential being sufficient to fire the control gap, thereby firing the main gap; the plus impulse is deducted from the minus potential on all the other condensers CI Without effect. I

The firing potential established at the control anode of DG-I by the short impulse is also applied back over resistance RI-I to the cathode of DG-Start, thereby reducing the potential across theimain gap of this tube below the sustaining value and extinguishing the tube; at this time the firing potential is also applied to condenser CZ-Start which temporarily charges and thereafter discharges over resistance R2, thereby delaying the restoration of full minus potential to the control anode of tube DG-I, and thus insuring the firing of the main gap in DG-I. When DG-I is fired the drop caused thereby in common resistance I85 aids in reducing the potential across the main gap in DG-Start, thus further insuring the return to non-fired condition of the DG-Start. With DG--I fired the drop in resistance R2I applies a plus biasing potential to the control anode of tube DG-II for firing of the control gap only in this tube when the next impulse is applied.

It may be noted here that the varister I8I and condenser I83 connected across the primary winding of transformer I82 are provided to reduce the rate of change of current in that winding when the main gap in tube DG-Start is extinguished, the purpose being to prevent the impulse in the secondary winding from firing the control gap of the Stop tube I and react upon the oscillatory circuit at this time. However, due to the unilateral characteristics of the varister I8I, the suddenly rising current at the time of firing the main gap of DG-Start during the Stop pulse will be forced through the transformer, inducing a potential in the secondary winding high enough to fire tube I89 and. cook the oscillator.

In the manner described above, the next short impulse from transformer I52 will fire tube DG-II and extinguish the tube DG-I, and subsequent impulses from transformer 152 will successively fire the tubes DG-HI, IV, V and DG-Stop, in each case extinguishing the preceding tube, so that at any time only one tube will be fired and during the time of a complete character code of seven pulses one tube will be fired at any time. The tubes DG will be fired at exactly equal intervals as determined by the short impulses from transformer I52 and the phase relation of the firing relative to the arrival over the circuit L of the front of the Start pulse may be determined by adjustment of the potentiometer I5I. The firing in succession of the DG tubes is indicated by curve E in Fig. 4.

The circuit through the main gap of tube DG-Stop may be traced from minus, over resistance RZ-Stop, main gap, left winding of relay I90, resistance I to plus. Relay I90 is normally operated to its spacing contact by the right-hand biasing winding, and when tube DG-Stop is fired operates to marking, thereby removing minus potential from conductor I92 and applying it to conductor I9I for control of the storing and transfer tubes, as will be described hereinafter. While tube DG-Stop is fired it causes the biasing potential to be applied over conductor I54 and resistance RI -Start to the control anode of tube DG-Start. At the end of the seventh cycle the tube DG-Stop is extinguished and relay I90 is restored to spacing. The timing of these relay operations is indicated by curve F in Fig. 4.

As referred to above, the firing of the tube DG-Start at the end of the seventh cycle causes an impulse to be produced in the secondary winding of the transformer I 82 which fires the control gap of Stop tube I80, thereby firing the main gap of this tube and cooking the oscillator I30. The impulse producing circuit and the distributor circuit thus will be restored to normal at the end of the seventh cycle and in time for the arrival of the next Start pulse.

The receiving circuit shown in Fig. 1 further includes five sets of storing gas tubes'SG and transfer gas tubes 'TG, .each adapted to store the corresponding selecting p l and transfer it to the output conductor 10,0 .ro'r use .as will be de scribed hereinafter. .These tubes are normally in non-conducting condition.

As shown in Fig. 1, the cathode of each storing tube SG is connected to .a potentiometer circuit from negative potentiometer 188, over resistances R3, R4, R5 to plus. The control anode of each tube SG is connected to acontrol potentiometer circuit from minus, over resistances R2, .35, 31, conductor I2 3, secondary winding .of .ti'ansfdriner I12, conductor in and contacts of relay llflfto plus or minus. The potential across the control gap of each tube .SG lthus depends on .the conditions in the control potentiometer circuittraced above. In the following description single values will be assumed for the .various potentials irivolved; these figures are .given foruth'e sake of illustration of the general principles invlvedfbther suitablevalues may be 'v'vorked' out by those skilled in this art without a departure Ironiith'e invention. With relay I20 in spacing position-the potential at the control anode of "the" SG tubes 'would'be full minus (or about -'-4Ovolts) with relay |20 in marking position thepot'ential at the control anode would be more positive (being changed by about +20 volts) With the cathodes of tubes SGtat -40 voltsthe potential across thecontiol gap would be zeroior spacing, and tar marking condition it would be about- 20 volts. With one of the distributor tubesDG-I-to V in conducting condition the plus biasing potential due to the drop (20 volts) inresistanceBTwill be superimposed 'upon the already established potential in the associated control potentiometer, rendering it more positive (by beuezo' yolpsi. These conditions are represented by curve L of Figure; as appliedparticularly td'the s'toriiig tube SG I for storingof' the' s'electi'rj-ig pulse'I. As shown by this curve the potential across the control gap is normally determinedby fireman;- ing position of relay [21f (20"vo1 ts'). "Afit''rthe Start transition the potential reg es to arm At transition I' thei'tube is fired (see curve;

E) and the resulting biasing potential 'rais'es the controlgap potential (to 20 'volt'sl'. When'relay I20 goes to marking (delayed) the controlfgap potential is further increased' it o d yeast- When tube DG-fI is extinguishedjat transition II the potential,is reduced ito 2 6 misread remains at this valuelexcept whilelrelay 128 goes to spacing, as during the pulses IV land" which are being assumed to be .Sbi cing the potential becomes zero.

h it w b seem-1cm. h .P P .-.5 T.- is speciallyconditloned 'bythe jfirlng of tube n and th me new time: t a in S G-I is further increased at this time rn zo voltsnto 40 was); it relay, I20 is 'jirijha o it th 'ii c f P e ti ass me t it about 70 volts'the tube remalnsfcuirentless.

The firingpotential'is cated 'ii I 'Since the transformer H2 is included in all the control potentiometer "circiiits'fffor' the tubes it is evident-that the impulsesfprodiiced the transformer "a about "are" center "of each sta e cycle will make all the SG control anodes more positive (by *40 volts). Only the 'SG tube which is :m acon'ditionedstate can be fired by the im-- pul'se, and only during a marking pulse. Thus, as shownbycurve' three conditions of positive potential add up during the impulse from transformerIJZ"tobxc'eed (by 10"volts) thefiring potential of tube SG- I. If, as "indicated by dotted linecurve portions in curves Aand'L, the pulse I had been spacing, the potentiaPaerossthe control gap during theimpuls'e would have been insuffici'ent (60 voltsl'to start the tube SG-J. Thus any one'oftheSGtubes may be started during a"markingpulseprovided the tube is conditioned by 'thedis'tribtitor'; The firing of the control gap automatically'switches to the main gap," 'wlfere the "main anode is connected over resistariceRrto plus." The tube remains fired un'til the Stop pulse. These conditions are indicated for tube :SG I by curve M in Fig. 4.

Inasmuch 'as the biasing potential from any particular distributor tub'e DG contributes "to the-building up of the potential on the control anode of the "associated SG" tube, the further change toward positive of the biasing potential due to an'impulsefrom transformer I52 at the end of fthe' 'cyclewill increase the control "potential on the SG "tube? To again consider tube SG-Ifwith this tube already firedth'e impulse would have no efi'ect. With the tube currentless during a spacingp'ulseI and with'the impulse rromnnsrormerl52 a voltage not in excess of thatfrorri transformer i't12"(40 volts) the compotential' applied across the control gap of tube SG-I' at 'the" end of the cycle would be insufl'icient to fire'theitube.

' Considering" "the particular condition of a marking pulse arriving early, it will for the sake of'eX-ainple be assumed that pulse I is spacing, tubDG-I is smear-1a tube SG-I is conditioned but not fired (contra gap potentiaIZO volts). Shortly before instant II the relay "I20 operates to marking, bringing the control g'ap potential onSG-I closento value (40 volts). "At instant Ilthe iiiipiilseirom transformer 152 is added to the eoiitrolpotential'. Therefore, in order topr'etent untimely" firing of SG-I the voltage (20v'01tS)" of this impmsemus't' bapfiiclabl-yl'ss "than that from transformer H2 (40 volts) ,so' that the'SG tube may be adjusted to discriminate" between them. The firing potentialof the SG tubes may be adjusted atf'potendamper 488; f-necessa yfa' potentiometer we may be provided "for each SGti' be, to make the firing"potentialindepehdent of the load from the med tubes? 'Theoperations of relay also react to some extent through re istances R6 and B1 upon the biasing potential establishedTby a1 fired DG tube for tl'ie' si'icceedingDG tubei The change m'biasing potential we to "thiscaus-"e shouldhe appreciably less'tliain the voltage of the" impulse; from transformerjlfl'ito nsure thejn'eirt DG tube will be 'iir'ed "by the impulse whilef relay I 20 is in spacing, and also to prevent the conditioned tube "from firing'if'relay' I 28"shOu1d 8b to marking. Th'e"biasing potential normally applied to tube DG-I wane thejtubepQ-Start is fired isof course independent ofrelayln (the drop in resistance'Rl-stalrt will still be assumed to be about 20 vents); When the iinpulse froin transfor' ner151i20 volts) arrives the sum of thetvvo potentials ('41) volts) exceeds cheering potential (awaits fdr t heonftrol'fgapj mpepo is fired and'D'G -II isbonditioned'." The biasing potential acumen:

the drop in resistance R2 (20 volts) with the;

plus or minus potential from relay I20 superimposed thereon, In the case of a spacing pulse the biasing potential would be reduced (to about 15 volts, more positive than full minus) and in the case of a marking pulse it would be increased (to about 25 volts), the resultant potential in either case should be insufficient to fire tube DG-II. With the impulse (20 volts) added from transformer I52, either of the resultant potentials (increased to 35 and 45 volts, respectively), should be sufiicient to fire tube DG-II.

- In the manner described above, an incoming signal may be stored on the storing gastubes SG, any one tube being fired during a corresponding marking pulse at the proper time, as controlled by the distributor tubes DG, and the remaining tubes being left currentless. Thus, for the assumed signal the tubes SG-I, II, III will be fired and tubes SG-IV, V will be extinguished.

Each of the five transfer tubes TG has its control anode connected to the potentiometer R3, R4, R5, and its cathode is connected over conductor I9I and normally open marking contact of relay I90. The potential across the control gap, when relay I90 goes to marking position and connects negative to conductor I9I, will normally be too low for firing of the TG tube. However, when the associated SG tube is fired the consequent drop over resistance R3 will drive the control anode of tube TG enough toward positive to permit firing. Thus, when relay I90 operates to marking aS tube DG-Stop is fired. any TG tube which is connected to a fired SG tube will have its control gap fired.

The main anode of each TG tube is connected through conductor I and resistor RII to a potential of +130 volts. Thus, the arc in the fired tubes will automatically switch to the main gap, thereby establishing an operating current over each conductor I00 associated with a received marking pulse.

The firing of the TG control gap tends to immediately increase the drop over resistance R; however, the charge on condenser C3 assures complete firing of the main gap by temporarily maintaining the potential across the control gap. When the main gap is fired the main gap potential reduces to the sustaining value (about 32 volts), due to the resistance included in the circuit from conductor I00 as will be described hereinafter. Due to the charges on condensers C4 and C5 the potentials on the TG control anode and on the SG main anode will temporarily be driven more toward negative thereby extinguishing these two gaps. Thus, the storing tubes, which were fired, are extinguished at the beginning of the Stop pulse. After the passing of the seventh cycle the tube DG-Stop isextinguished and relay I90 returns to spacing position, thereby extinguishing the TG tubes and conductors I00 will be restored to their normal potential.

With the tube DG-Start fired and the oscillator I30 cooked the entire receiving circuit is restored to normal ready for the next Start pulse, having passed a marking current over conductors I00-I, II, III to the associated circuit, and no current over conductors IOU-IV, V.

It will be noted from the description given above that the tubes TG responding to a spacing pulse will apply full plus potential to the output conductors and responding to a marking pulse will apply a reduced plus potential to the output conductors during the Stop pulse. However,

12 for the purpose of establishing the reverse 'con' dition in outputi'conductors from the distributor circuit in Fig. 1, a :set of transfer vacuum tubes TV is provided, having a set of output conductors IOI. Each vacuum tube TV has its control grid connected to an intermediate point of the potentiometer R9, RIII, RI I', connected from minus to plus, and normally the potential applied to the grid is high enough. to cause a flow of plate cur- .rent from plus through the resistance BIZ and the cathode-anode path of the tube to ground, thereby establishing a potential drop in resistance Rl2, Thus, under normal conditions the output conductors II will be at a potential lower than the plus potential.

. Again, assuming that the storing tubes SG-I, II, III will be fired and that the tubes SG-IV, V will be extinguished at the time the Stop pulse arrives and operates relay I90 to marking, the

corresponding TG tubes will be fired and extinguished, respectively. Thus, considering the code unit I, the current flow in the resistance RI I will be increased thereby driving the grid potential of tube TV-I less positive. The tube becomes currentless, thereby eliminating the drop in resistance RI2 so that full plus potential will be applied to conductor I 0 I-I. In the case of the code unit IV the TG, tube will not be fired so that the tube 'I'V-IV will continue to carry plate current and to maintain the reduced plus potential on output conductor I0 I-IV.

In this manner the TV tubes responding to a marking condition will apply high plus potential to the output conductors and those responding to spacing will apply a reduced plus potential to the output conductors during the Stop pulse. This mode of operation is particlarly suitable for the circuit arrangement shown-in Fig. 2, as will now be described.

The decoding circuit shown in Fig. 2 is at least in part based upon the principles of the circuit shown in Fig. 1 of Patent 2,458,030 granted J anuary 4, 1949, to W. T. Rea. Thus, the circuit of Fig. 2 includes five code unit or inverter circuits I, II, III, IV and V connected over pairs of conductors A and B to two code discriminating circuits 220 and 230 responsive particularly to the codes for Fig and Letters, respectively. The system, as shown, also includes a translating arrangement connected to the conductors'A and terminating in the-deflecting plates of a cathode ray tube 250 for selective deflection of the beam in accordance with each incoming code and for display of the corresponding symbol. This circuit is also adapted for operation with the distributor circuit shown in Fig. 1.

7 Each of the inverter circuits I to V thus includes a vacuum tube V and resistances RI, R2, R3 and R5 connected to plus and minus potential and to a pair of conductors A and B, substantially as shown in Fig. l of the copending application imposed upon its input conductor 20I by the corthe conductor B will have low potential.

responding transfer vacuum tube TV in Fig. 1 over a conductor I0 I. I When the tube SG in Fig. 2 is non-conducting the tube V will be conducting and the conductor A will have high potential and The control anode of tube SG is connected to a point of the potentiometer circuit formed by resistances 202, 203 and-204c0nnected between ereun a drlas nd. hvs a a esi r pet i l.

I3 applied thereto (of 30-40 volts) under this condition the condenser 200 is charged to the same potential. The cathode is connected over the conductor I92 and over the normally closed spacing contact of relay I90 to minus.

Assuming the circuit as shown in Fig. 2, to be in the condition prevailing during the seventh cycle, when relay I90 is operated to marking thereby disconnecting minus from the cathodes of the SG tubes, these tubes will all be extinguished. Further assuming that the pulse I is marking and that consequently the transfer tube TV-I in Fig. 1 is non-conducting during the seventh cycle, then the potential on the condenser 200-1 and on the control anode of tube SG-I will be sufiicient for firing of'tn'etube when at the end of the seventh cycle relay I90 again applies minus to the cathode. The condenser 200 will retain a sufiicient charge during the travel time of relay I90 to assume proper firing of the tube. As a result the main gap is fired over resistance Rl-I to plus, which cuts off tube V-I and causes the inversion of the potentials on the conductors A-I and BI. The tube 'SG-I willremain fired until the next seventh cycle, thus storing the marking condition until the Stop pulse of the succeeding signal.

Further assuming that the pulse II is spacing, the tube TV-II in'Fig. 1 will be conducting during the seventh cycle, in whichcase the potential on condenser 200-11 and the control anode of tube SG-II will be low and insufficient to fire the tube, when relay I90 returns to spacing and completes the cathode circuit 'to minus. The conductors A-II and 'B-II thus retaintheir normal potentials undisturbed.

Similar functions-takeplace inall thecode unit circuits I to V depending upon the markingand spacing condition of the corresponding pulses of the-code signal, so that the 'potentialson the conductors A and B will be correspondingly disposed and will retain such disposition of potentialsduring the reception of the succeeding signal until the Stop signal thereof.

The cathode ray tube 250 may -be "of conventional type and includesthe-usual elements-such as cathodes 253 and elements 254, 255 and 256 for projecting and focusing the beam, these elements being connected to suitable potentials on potentiometer 252 connected to the source of directcurrent 25 l. A pair of horizontal positioning or deflecting plates 26| and 262 and a pair of vertical positioning o'r deflectingplates263 and 264 are arranged for deflecting the beam horizontally and vertically, respectively, in accordance with marginal potentials impressed upon these plates through resistances 281,282,283, "284,285 and 2-86 by the coderesponsive'circuit. The tube elements are enclosed in a sealed vessel 2 B0, usually of glass, containing an inert gas'at lowpressure. The enlarged end of thetube 260 is coated with'a suitable material adapted to be activated by the beam for luminous display 'of the beam spot. The reading surface thus provided has a display screen 210 incorporated-therein containing the upper and lower case-symbols represented by the code,these symbols being arranged in horizontal and vertical lines, as shown-more in'detail inF'ig. 3. The object is to deflect the floating beam in accordance with each incomin'gcode signal to strike a corresponding-symbol on the screen 210 and thereby make the symbol visible or optically effective for *recording. The screen maybe placed in any convenient manner to- 'either producea shadow of a symbol onen illuminated 14 background outlined by the beam or ta produce an illuminated symbol on a dark background. The beam will be at :rest on a selected symbol at least during the first six cycles of operation of the circuit in Fig. v2 and the luminous material in the screen 210 may have .sufiicient persistence of luminosity to permit the reading of successive symbols by the eye, even at the speed of normal teletypewriter operation.

The field of symbols, shown in Fig. .3 .includes a plurality of horizontal rows '1 to B and vertical rows 11 to h. The Letters are disposed in the odd numbered rows and the Figs in the even numbered rows. Other arrangements of the two cases may however be provided. The deflecting plates 261,262, 26 3 :and 260 are indicated in this diagram in their relation to the rows. The adjustments in the circuit are such that the beam will be focused -on the vacant space 5.,d in response to an all spacing code, for which condition all the deflecting plates receive high potential. The vacant :space may, of course, be differently chosen, if desired.

The plate 251 is connected "through resistance 28! to the conductor A-l and thus will have high plus potential iora spacing ipulse I and low plus potential for a marking pulse II. The :change from high to low potentialwill pause the beam to bedefiected'four spaces :to the right Iromany position it may happen to occupy.

The plate 262 is connected through :resistance 282 to conductor A-V and through resistance 283 to a pointc on resistance FRI-J11. Thus :for a marking pulse III the .point c on resistance Ri will beat an intermediate potential and tor a spacing pulse III the point cwill .be at high plus potential. For a mar kin'g pulse V'the resistance 282 will receive low plus potential and for a spacing plus V resistance1282 :will :receive high plus potential. I'he combination of these potentials applied to resistances i2 82 Land .283 will variously afiect the potentialapplied to thezplate 262. I hus with both resistance 282 and 203 receiving high potential for 'spacing .plus :III .and V there will beno eftecton' the beam. Withhigh potential on resistance 282and low onresistance 2 83, half of thediilerence will be "applied .to plate 262,-eausing the beam to move'two spaces to the left. With intermediate lpotentialon resistance 283 and high potential on resistance 202, only half of the difference ibetween these potentials will be applied to plate @262, causingithe beam to move one space "to the lleft. WithFintermediate potential on resistance .283 and low potential .on resistance 282 the "beam twill amove three spaces to the left. This general;;principle of potential division :may, of course, be extended to include control of plat'e22 62 :byazone JO! more additional code unita-eitherwithinthe five-unit code .or in acode with six or more units.

The plate 2 6.3 is -'-connected IDVBI resistance .284 to the conductor..-A-II to receivehigh potential for a spacing pulse II and low potential fora marking pulse II. The change :fromhigh tolow potential'will move the beam four spaces down. The plate .264 is connected through resistances 285 and 286 to receive "combination potentials from the conductor-A-IV and from the point 01 on resistance 2.1] in the circuit 210. As will be explained hereinafter, the tube V .2l0 will be in spacing condition, that is, non-conducting when the Letters condition iseestablished and in marking or conducting: condition when the Fig condition is established. The, pointdthus-willtbeaat hizhpluslpotentialior letters and atintermediate potential for Fig. Thus with low potential on resistance 285 for a marking pulse IV and high potential onresistance 286 for Letters the beam will move up two spaces. With Letters changed to Fig there would be an intermediate potential on resistance 286 which with low potential on resistance 285 will move the beam up three spaces. With a spacing pulse IV and Fig the high potential on resistance 285 and intermediate potential on resistance 286 will move the beam up one space.

Thus for the sake of example, it will be assumed that the beam is focused on the space 5,d for an all spacing code. For the first signal having the code 1----, the beam will move to the space SJL displaying the corresponding symbol E. For the next signal having the code 12---, the beam moves four spaces down, showing the corresponding symbol A." For the next code 123--, the beam moves one space left, showing the symbol U. For the next code 1234-, the beam moves two spaces up, showing the symbol K. For the next code being 12345, the beam moves to the space 3,e corresponding to Letters.

In a similar manner the operations for any other code combinations may be traced.

Generally speaking a reduction in potential on a plate in the cathode ray tube equal to the full difference between high and low plus potential will deflect the beam four spaces away from the plate. When the reduction in potential is applied through a pair of resistances, such as 282 and 283 or 285 and 286, the deflection will be only two spaces away from the plate. When the reduction is further divided as by the resistance 283 being connected to the mid-point of resistance RI or as in the case of resistance 288 being connected to the mid-point of resistance 2, then the beam will be deflected only one space away from the plate.

It should be understood that the shifting of the beam over 1, 2 and 4 spaces in different combinations by a pair of plates may be accomplished by applying corresponding potentials to one of the plates and maintaining a constant potential on the other plate, or that these three selective actions may be apportioned between the two plates of a pair in any manner, the starting point of the beam being changed accordingly.

It will thus appear that with two pairs of positioning elements arranged in quadrature about the floating beam and with suitable use of potential dividers as described herein to supply the required marginal positioning force, a single tube may be used for selective action in response to codes of more than five units. Thuswith a code of n units, the field may contain 2" spaces. Of these, 2 spaces may be selected in response to m units of the code applied to one pair of plates, and the remaining 2"-- spaces may be selected in response to nm units applied to the other pair.

It will be noted that the operations traced above result in the display of symbols only in odd numbered horizontal lines in which the letters are displayed. In order that the symbols in the even numbered rows, viz., the figures, may be displayed by corresponding codes it will be necessary to temporarily shift the beam upward one space. This will be accomplished by the transmission beiore the symbol of the code 12-45 for Fig which will be received in the circuit 220 where the tube 220V would become non-conducting. When this happens the potential applied from the potentiometer of resistances 221,222, 223 to the control anode of-the associated gasfilled tube G will be made sufficiently positive to fire the control gap and consequently fire the main gap of this tube. The current in the main gap flows from minus over resistance 225, main gap, resistance 222 to plus. Resistance 225 being included in a potentiometer circuit with resistance 212. The potential drop therein makes the grid potential in the tube V-ZIO more positive, thus rendering the tube conducting; the consequent drop in resistance 2 will decrease the plus potential applied over resistance 238 to the plate 2% which thus will shift the beam upward one space. The tube G428 will remain fired during subsequent signals; thus upon the reception of the code for Fig all subsequently received codes will cause the beam to display the corresponding symbol in any of the even numbered rows.

When at any time thereafter the code for Letters is received the tube V-238 will be rendered non-conducting, thereby firing the tube G430 in the same manner as explained for the tube G-228. Resistors 23I, 282 and 233 have the same relation to tubes V-238 and (3-238 that resistors 22L 222 and 228 have to tubes V-22G and G428. The condenser 22% having been charged by the potential drop in resistance 224 since the firing of the tube G423, its potential at the time of firing of tube drives'the potential on the main anode of tube (i-228 to a value less than the sustaining potential thereby extinguishing the tube G-ZZQ. As as result the tube V-2l8 is again rendered non-conducting, thereby increasing the plus potential on plate 26 3 and lowering the beam one space for subsequent display of symbols in the odd numbered rows.

The gas tubes G-22Q and 6-236 are mutually extinguishing through the condenser 226 which will be charged alternately across the resistances 224 and234.

It should be understood that the gas tube (El-228 and the vacuum tube V-2l0 may be arranged as tubes SG-VI and V-VI for direct response to a sixth code unit, in which case the Letters circuit 238, of course, would be unnecessary. a

It should furthermore be understood that the positioning plates in the cathode-ray tube may be connected to the B conductors instead of the A conductors for each code unit, or that some of the connections may be made to the A conductors and theothers to the B conductors, with corresponding relocation of the symbols on the display screen 278.

The system, as shown in Fig. 2, may, of course, be used for selecting other circuits, besides the circuits 228 and 238, in response to other code combinations. Thus, a circuit may be provided which will operate an audible signal in response to Fig-S in accordance with general practice.

The cathode-ray tube 258 may be readily adapted for circuit selection instead of for decoding into visible symbols. For this purpose the field of letters 270, shown more in detail in Fig. 3, should be replaced by a field of separate cir-' cult elements mounted on the end surface of the tube and connected for selective control of corresponding circuits in response to contact with the floating beam. The energization of individual circuits by the beam for the duration of a signal may be accomplished by different means. Reference may be had to United States Patent 2,057,773, issued to Finch on October 20, 1936,

which in Fig; I shows single contact elements transmitting impulses into separatecircuits by direct contact with the beam. In the United States Patent 251%;098, issued to Skellett on March 26, 1 940; a similarbut intensified action is secured by se condaryionization between double contact elements under impingement by the beam. Any well-known means may be usedto establish a time margin in each circuit to insure positive-control during the exposure time, and to exclude control while the beam travels between positions during the stop pulse.

A diagrammatic showing of such an arrangement is given in Fig. 5. Onlya portion of the field of contacts or electrodes is shown. The common electrode 2H provides a plurality of compartments 2'12 arranged in rows similar to those shown in Fig. 3. Within each compartment an individual electrode 213 is mounted and is connected through the tube wall to an external circuit. Each compartment and its electrode is aligned with the direction of the beam so that when struck the space between them will be ionized and cause a current to flow between the common conductor 215 and the individual conductor selected.

For number checking or identification on a IO-digit basis, the tube may have x10 targets selectable by a 'Z-unit permutation code. With two such tubes in cooperation, 10,000 numbers could be checked or selected by two '7 -unit codes.

What is claimed is:

1. A permutation code signal responsive system comprising a plurality of code responsive circuit means, one for each unit of the code, and each having an output terminal, a cathode ray tube for translation of the incoming signals and including a first and a second plate for deflecting the beam horizontally and a third and fourth plate for deflecting the beam vertically, each of said plates being connected to a corresponding one of said output terminals, each of said receiving circuit means being adapted to establish at its output terminal two diiferent potentials relative to the beam potential in response to the alternate conditions of its assigned code unit for effecting two different deflections of the beam.

2. A permutation code signal responsive system comprising a plurality of code responsive circuit means, one for each unit of the code, and each having an output terminal, a cathode ray tube for translation of the incoming signals and including a first and a second plate for deflecting the beam horizontally and a third and a fourth plate for deflecting the beam vertically, each of said plates being connected to a corresponding one of said output terminals, each of said receiving circuit means being adapted to establish at its output terminal two different potentials relative to the beam potential in response to the alternate conditions of its assigned code unit for effecting two diiferent deflections of the beam and one of said plates also being connected to another one of said terminals for superimposition of the voltages at the said two terminals for effecting still another different deflection of the beam.

3. A decoding system comprising first voltage control means having an output terminal and being responsive to a first unit of the code to supply two different voltages to said terminal in response to the alternate characteristics of the unit, second voltage control means similar to said first voltage controlmeans for similarly supplying voltages to its terminal, third voltage control means similar to said first voltage control means for similarly supplying two difierent voltages to its terminal at least one of which is different from the corresponding voltage of said first voltage control means, and a cathode ray tube having a first plate connected to saidfirst voltage control means for deflecting the beam to two different positions in response to said different voltages and a second plate connected to said second and third voltage control means for deflecting the beam to four different positions in response to the combined said different voltages.

4. A translating system for a permutation code including 2" permutations of code units having two alternate characteristics comprising a translating device having floating selecting means and four positioning means arranged in quadrature about said floating selecting means for selective positioning thereof in a field of 2" spaces for selective action, said system further comprising control circuit means having n code responsive means each adapted to apply high and low positioning forces to one of said positioning means in accordance with the alternate characteristics of the assigned code unit, m of said responsive means being assigned to one opposed. pair of said positioning means and n-m of said responsive means being assigned to the other opposed pair.

5. A translating system for a permutation code including 2 permutations of code units having two alternate characteristics comprising a translating device having floating selecting means and four positioning means arranged in quadrature about said floating selecting means for selective positioning thereof in a field of 2" spaces for se; lective action, said system further comprising control circuit means having 11. code responsive means each adapted to apply high and low positioning forces to one of said positioning means in accordance with the alternate characteristics of the assigned code unit, m of said responsive means being assigned to apply marginal forces to one opposed pair of said positioning means to position said selecting means se lectively in any one of 2" positions and nm of said responsive means being assigned to apply marginal forces to the other opposed pair'to position said selecting means selectively in any one of 2""" positions.

6. A translating system for a permutation code including 2" permutations of code units having two alternate characteristics comprising a translating device having floating selecting means and four positioning means arranged in quadrature about said floating selecting means for selective positioning thereof in a field of 2" spaces for selective action, said system further comprising control circuit means having n code responsive means each adapted to apply high and low posis tioning forces to one of said positioning means in accordance with the alternate characteristics of the assigned code unit, said code responsive means being adapted to produce equal high potentials and equal low potentials for the application of said high and low pQ itioning forces, and said control circuit means further including potential dividing means connected to receive high and low potentials from said code responsive means for proportioning of some of said high and low forces to effect 2" combinations of forces.

'7. A translating system for a permutation code including 2" permutations of code units having twoalternate characteristics comprising a translating device having floating selecting means and 19 four positioning means arranged in quadrature about said floating selecting means for selective positioning thereof in a field of 2" spaces for selective action, said system further comprising control circuit means having n code responsive means each adapted to apply high and low positioning forces to one of said positioning means in accordance with the alternate characteristics of the assigned code unit, said responsive means being adapted to produce equal high potentials and equal low potentials for the application of said high and low positioning forces and said control circuit means further including potential dividing means connected to receive said equal high and low potentials for proportioning of some of said high and low forces to effect 2 combinations of forces applied to one opposed pair of said positioning means and to efiect 2 combinations of forces applied to the other opposed pair for the positioning of said selecting means in any one of said 2 spaces.

8. A translating system for a permutation code including 2 permutations of code units having two alternate characteristics comprising a cathode ray tube having two pairs of juxtaposed plates for positioning of the beam in a field of 2 spaces for selective action, control circuit means for said tube including n code responsive means each adapted to apply high and low positioning potentials to one of said plates in accordance with the alternate characteristics of the assigned code unit for positioning of the beam in 2" spaces of said field, a code discriminating circuit having a receiving branch connected to each of said code responsive means for combining said high and low potentials into a single discriminating potential varying to represent the different incoming code combinations and selective means connected to receive said single potential and responsive to a predetermined value of said single potential 1 representing a predetermined code combination to alternately apply high and low positioning potentials to one of said plates to cause the beam to be subsequently positioned by said code responsive means alternately in one and the ot of the 2" spaces.

9. A translating system for a permutation code including 2" permutations of code units having two alternate characteristics comprising a cathode ray tube having two pairs of juxtaposed plates for positioning of the beam in a field of 2 spaces for selective action, control circuit means for said tube including n code responsive means each adapted to produce high and low potentials in accordance with the alternate characteristics of the corresponding code unit and potential dividing means connected between at least two of said code responsive means to produce intermediate potentials in accordance with the alternate characteristics of the corresponding code units, two code discriminating circuits each having a receiving branch connected to receive high and low potentials from each of said code respon sive means in accordance With the code requirements for the assigned symbol, said receiving branches in each being interconnected to combine said potentials into a single discriminating potential varying as the different code combinations are received, each of said discriminating circuits further having selective means connected to be selectively responsive to a predetermined value of said varying potential representing the assigned symbol for selective action, storing means for producing high and low potentials and connected to be responsive to the selective actions of said two selective means, alternately, to alternately produce said high and low potentials, and potential dividing means connected between said storing means and at least one of said code responsive means to produce intermediate potentials in accordance with the alternate characteristics of the corresponding code unit and the alternate code combinations of the said two assigned symbols, said two pairs of plates being connected to receive said high, intermediate and low potentials for positioning of said beam in any space in said field.

10. A translating system in accordance with claim 9 in which said tube has 2"+ electrodes distributed in said 2"" spaces each adapted to produce a current flow in an associated circuit when selectively engaged by the beam.

11. In a decoding system for a permutation code having 11 code units, n pairs of receiving circuits having high and low potentials of the same polarity and responsive to the code units to interchange said high and low potentials within each pair, a cathode ray tube having a pair of horizontal and a pair of vertical beam positioning means, and a plurality of potential dividers connected to said receiving circuits to apply one or the other of said potentials to said positioning means and to apply varying potentials intermediate said high and low potentials to said positioning means for positioning of the beam into 2" distinctly different positions in response to the different code permutations.

12. A translating system for permutation code signals comprising a cathode ray tube having a pair of opposed plates for positioning of the beam in a field of spaces for selective action, code responsive means for each code unit for establishing simultaneous high and low potentials in accordance with the alternate characteristics of the assigned code unit, a decoding circuit having a receiving branch connected to each of said code responsive means for combining said high and low potentials into a single discriminatory potential representing the different incoming code combinations, and selective means connected to receive said single potential and responsive to a predetermined value thereof to alternately apply high and low potentials to one of said plates for correspondingly varying the position of the beam.

13. In a translating system for permutation codes, a selector mechanism comprising a plurality of selector devices equal in number to the selecting elements of the code and each conditionable in accordance with either of two selecting conditions of said elements, a cathode ray tube having pairs of deflecting electrodes disposed in quadrature, connections from said selector devices to said deflecting plates for impressing on said plates combinations of electrical potentials to cause the deflection of the cathode beam to any one of a plurality of positions equal to the selecting capabilities of the code, and decoding means connected to said selector devices and effective in response to a particular code combination for superimposing upon one of said pairs of plates an electrical potential which, in combination with said other electrical potentials, causes the deflection of said beam to any one of a like plurality of other positions.

14. In a translating system for permutation codes, a selector mechanism comprising a plurality of selector devices equal in number to the selecting elements of the code and each conditionable in accordance with either of two selecting conditions of said elements, a cathode ray tube having pairs of deflecting electrodes disposed in quadrature, connections from said selector devices to said deflecting plates for impressing on said plates combinations of electrical potentials to cause the deflection of the cathode beam to any one of a plurality of positions equal to the selecting capabilities of the code, and decoding means connected to said selector devices and effective in response to a particular code combination for superimposing upon one of said pairs of plates an electrical potential which, in combination with said other electrical potentials, causes the deflection of said beam a fixed distance from any one of said positions to a corresponding one of a like plurality of other positions.

15. In a translating system for permutation codes, a selector mechanism comprising a plurality of selector devices equal in number to the selecting elements of the code and each conditionable in accordance with either of two selecting conditions of said elements, a cathode ray tube having pairs oi deflecting electrodes disposed in quadrature, connections from said selector devices to said deflecting plates for impressing on said plates combinations of electrical potentials to cause the deflection of the cathode beam to any one of a plurality of positions equal to the selecting capabilities of the code, means for superimposing upon one of said pairs of plates either of two electrical potentials which, in combination with said other electrical potentials, causes the deflection of said beam to any one 01' said positions or to any one of a like plurality of other positions, and decoding means individually responsive to two particular code signals for causing said two electrical potentials to be produced.

16. In a translating system for permutation codes, a selector mechanism comprising a plurality of selector devices equal in number to the selecting elements of the code and each conditionable in accordance with either of two selecting conditions of said elements, a cathode ray tube having pairs of deflecting electrodes disposed in quadrature, connections from said selector devices to said deflecting plates for impressing on said plates combinations of electrical potentials to cause the deflection of the cathode beam to any one of a plurality of positions in any one of a plurality of rows, decoding means connected to said selector devices and effective in response to a particular code combination for superimposing upon one of said pairs of plates an electrical potential which, in combination with said other electrical potentials, causes the deflection of said beam to any one of a plurality of positions in any one of a plurality of other rows alternating with said first-mentioned rows.

WILTON T. REA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,587,122 Harlow 1 June 1, 1926 1,917,294 Carr July 11, 1933 2,132,213 Locke Oct. 4, 1938 2,267,827 Hubbard Dec. 30, 1941 2,283,383 McNaney May 19, 1942 2,361,766 Hadekel Oct. 31, 1944 2,442,792 Marrison June 1, 1948 FOREIGN PATENTS Number Country Date 567,451 Great Britain Feb. 14, 1945 

